1. Field of the Invention
The present invention relates to a technique for measuring traffic of a packet-flow transmitted over a network for packet communication. More particularly, the present invention relates to a technique for measuring traffic at short time intervals so as to determine traffic quality accurately.
2. Description of the Related Art
As for a conventional traffic quality measurement apparatus targeted for packet communication, the purpose for using the apparatus is to measure traffic at the network level. Thus, the conventional traffic quality measurement apparatus mainly provides functions for measuring traffic volume over a long time period for a line as a whole, each protocol, each network layer and the like.
However, according to the above-mentioned conventional method, it is impossible to specify a packet-flow generated by a particular application using the network, to analyze the influence exerted on the packet-flow by the network, and to obtain traffic quality data necessary for adjusting the application to operate properly in the network.
That is, since the purpose of the conventional traffic quality measurement apparatus is to measure traffic over a long time period, time-resolution for measuring the traffic is more than one second. Therefore, traffic characteristics can not be obtained for a particular application such as a streaming service application.
Bandwidth required for the network for providing a streaming service including images and sound depends on its method of coding, and the bandwidth is discussed by using average bandwidth per second. However, software for sending coded data to the network performs its data sending processes independently of coding processes. In addition, the operation cycle of the software depends on the operation time unit of the task management system of the operating system on which the software is executed, and the operation cycle is generally from several milliseconds to several tens of milliseconds. That is, quality management for streaming traffic sent over the network requires measuring traffic-behavior with time-resolution higher than that of the conventional method.